Acoustic device



ACOUSTIC DEVICE Filed May 2, 1929 INVENTOR HENRI CHlREI ATTORNEYPatented Sept. 13, 1932 HENRI GHIREIX, OF PARIS, FRANCE ACOUSTIC DEVICEApplication filed May 2, 1929, Serial No. 359,823, and in France May 3,1928.

This invention relates to acoustic devices. More particularly it relatesto the means for supporting the diaphragm of such a device.

The object of the present invention is to disclose a number of improvedmethods of supporting the diaphragm of an acoustic device such as asound reproducer.

According to the present invention a supporting band or strip made from"flexible material is placed underneath the edge of the sound reproducerdiaphragm so as to form a flange of circular shape tending and adaptedto counteract slipping of the base of the cone diaphragm in its plane.This supporting band is folded or curved back or thickened orreinforced, as shown.

In the case of coupling two conical tympana opposing each other at theirapices, another improvement consists in choosing one of them of adiameter considerably smaller than the other. Among other things, thiscauses an improvement in the faithfulness of reproduction.

The invention will be better understood by reference to the accompanyingdrawing and the following description thereof covering certainembodiments by way of example. In

the drawing Figure 1 illustrates one form of my invention,

Figures 2 to 5 illustrate modifications thereof, and Figure 6illustrates a modification having a pair of tympana.

In the drawing, A designates the band of soft material which theperiphery of the tympanum E engages. B is the groove in which the band Ais lodged. Figure 1 shows a solution in which the band A is bent back soas to form aflange or collar. The two thicknesses of the material may bepreferably held in their respective positions by sewing with thread,gluing or cementing, clips, or the like.

Referring to Figure 2, the band A comprises a portion raised at a rightangle along the peripheral border or edge of the groove B.

Figure 3 comprises a band A of two superposed thicknesses, the insidediameter of the second thickness or layer being larger than that of thetympanum.

Figures 4 and 5 show two other modifications in which the band A is heldby the aid of a circular spring F which is preferably in the form of ametallic reed. The band A is folded or bent back all around in thegroove B.

Figure 6 shows a modification in which two tympana of differentdiameters are arranged so that they oppose each other at their apices.The edges of the tympana are supported as in the other modifications.

I claim whose rim bears upon said concave surface.

2. Acoustic apparatus comprising two supports of diaphragms, asupporting element lodged in each support, each element supporting theborder of a conical diaphragm and presentlng a concave surface 1n theneighborhood of the line of support of this border, a portion of saidconcave surface situated outside the periphery of the diaphragm formingan angle with the plane of the base of the cone which is much largerthan the angle between the generatrix of the cone and the plane of itsbase, the two diaphragms being united at their apices and one having adiameter considerably smaller than that of the other.

HENRI CHIREIX.

